標題: Origin of Extended UV Stability of 2D Atomic Layer Titania-Based Perovskite Solar Cells Unveiled by Ultrafast Spectroscopy
作者: Thilakan, Anusha Puliparambil
Li, Jia-Xing
Chen, Tzu-Pei
Li, Shao-Sian
Chen, Chun-Wei
Osada, Minoru
Tsukagoshi, Kazuhito
Sasaki, Takayoshi
Yabushita, Atsushi
Wu, Kaung-Hsiung
Luo, Chih-Wei
交大名義發表
電子物理學系
National Chiao Tung University
Department of Electrophysics
關鍵字: perovskite solar cell;ultrafast mechanism;pump-probe technique;UV degradation;two-dimensional metal oxide;electron transport layer
公開日期: 19-六月-2019
摘要: The inherent instability of UV-induced degradation in TiO2-based perovskite solar cells was largely improved by replacing the anatase-phase compact TiO2 layer with an atomic sheet transport layer (ASTL) of two-dimensional (2D) Ti1-delta O2. The vital role of microscopic carrier dynamics that govern the UV stability of perovskite solar cells was comprehensively examined in this work by performing time-resolved pump-probe spectroscopy. In conventional perovskite solar cells, the presence of a UV-active oxygen vacancy in compact TiO2 prohibits current generation by heavily trapping electrons after UV degradation. Conversely, the dominant vacancy type in the 2D Ti1-delta O2 ASTL is a titanium vacancy, which is a shallow acceptor and is not UV-sensitive. Therefore, it significantly suppresses carrier recombination and extends UV stability in perovskite solar cells with a 2D Ti1-delta O2 ASTL. Other carrier dynamics, such as electron diffusion, electron injection, and hot hole transfer processes, were found to be less affected by UV irradiation. Quantitative pump-probe data clearly show a correlation between the carrier dynamics and UV aging of perovskite solar cells, thus providing a profound insight into the factors driving UV-induced degradation in perovskite solar cells and the origin of its performance.
URI: http://dx.doi.org/10.1021/acsami.9b02434
http://hdl.handle.net/11536/152210
ISSN: 1944-8244
DOI: 10.1021/acsami.9b02434
期刊: ACS APPLIED MATERIALS & INTERFACES
Volume: 11
Issue: 24
起始頁: 21473
結束頁: 21480
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